9: The organic perfectibility of man

Concordet asserted that if man could be organically perfected, his lifespan would be indefinite. That is, through an improvement in medicine, a social order that addresses the causes of transmissible and contagious disorders, more wholesome food and habitations, a sufficiency of exercise, etc., the causes of death would be eradicated and, while man may not become absolutely immortal, this lifespan would be immensely increased.

Malthus considers this notion to be "unphilospohical" and entirely unwarranted by any evidence of the laws of nature. He does concede that variations in the duration of human life have been observed, those who are fortunate and privileged live longer than others who are less fortunate and subject to routine deprivation - but the notion that lifespan can be expanded indefinitely is an extravagant fancy. With regard to the duration of human life, there has not been any evidence that there ever has been a society of men whose lifespan has been indefinite, or even significantly extended.

He then turns to the example of animals: those who breed animals can do so in away that accentuates certain features, but only to a certain degree. By careful breeding, the heads and legs of Leicestershire sheep have been reduced as compared to other breeds, but it would absurd to thing that this could be constantly effected, to the point where sheep could be created with a head and legs as small as those of a rat.

The same kind of perfectibility has been witnessed in plants, where through selective cultivation a plant can be coaxed to produce a larger flower, more plentiful fruit, a taller stalk, etc. The example is given of carnations, whose blossoms have been increased significantly by cultivation - but no-one has yet produced a carnation blossom the size of a cabbage, nor would any experienced gardener assert that it were at all possible to do so.

So, too, does Malthus concede that human life could be extended by breeding and cultivation - but just as there are limits within the animal and plant species, so to is there a limit to the human species. That is, it is conceivable we can extend human life, to two or three times the present duration, but by no means indefinitely.

Even at that, there are doubts, as evidenced by attempts at improvement within the human race. Certain families have attempted, through selective mating, to improve their bloodlines - such as the Bickerstaffs, who are side to have been successful in lightening the skin and increasing the height of their line over several generations (resulting also in "some capital defects in the constitutions of the family). But there is no way practicable or conscionable method to practice eugenics on a societal level.